Excavator tooth retaining assembly

ABSTRACT

Retaining pin assemblies for use in releasably securing an excavating tooth or point to a mounting adaptor. Each pin assembly includes one or more holders insertable lengthwise in registering apertures in the adaptor and tooth and movable thereafter widthwise to cause interengagement. The holder and the apertures are provided with complementary portions. A locking member is inserted after engagement of the pin to fix the adaptor and tooth together.

TECHNICAL FIELD

THIS INVENTION relates to improvements in and relating to excavatortooth retaining assemblies.

BACKGROUND ART

More particularly, the invention has reference to novel retaining pinconstructions and arrangements for use in releasably securing anexcavating tooth or point or tip (hereinafter for convenience called "aground-engaging tooth point member") to its mounting adaptor. The latteris conventionally of the type having a forwardly disposed nose portionand a rearwardly dispose base portion, and the tooth point member has asocket or pocket formed in its rear section for receiving said noseportion of the adaptor.

Such arrangements are usable in various applications, the most commonbeing a loading bucket as used by draglines, front end loaders, trackedearth moving machines and the like. The ground engagement of the toothpoint members causes them to become worn and thus ineffective over aperiod so that they require to be replaced. Thus, the nature, type,disposition and accessibility of the retaining pins used for securingthe tooth point members to their adaptors can be most important relativeto achieving desirable removability, while being efficient in alloperational aspects.

Over many years there has been considerable development and improvementsin the art of connecting tooth point members to adaptors by suitableretaining pin means. It is currently sought to provide a retaining pinwhich may be easily fitted in its operative position, will remain thereduring normal operations until such time as the ground-engaging toothpoint member requires replacement, and then will be easily removed. Formany years such a standard type of retaining pin has been insertedthrough registering apertures extending respectively through the toothpoint member and adaptor and forcibly hit with a hammer until caused tobe deformed and thereby retain the tooth point member by an interferencefit. Removal of the deformed pin is then achieved by again hitting itwith a hammer to force it out of the apertures a procedure which may bevery difficult and time consuming. Alternatively the retaining pin mayfall from the apertures unintentionaly during operation when operationalforces may act on the pin in the direction of pin removal and force itout.

U.S. Pat. No. 4,326,348 of Esco Corporation and Australian Patent No.620074 of Caterpillar Inc. show pin fastening assemblies which overcomethe problem of pins inadvertently falling out of their apertures duringoperation by having the pins disposed horizontally. This method, howeverhas largely been rejected by the industry due to the difficulty inaccessing the apertures from the sides of the tooth point members as thetooth point members are disposed in a side by side configuration withinsufficient working space therebetween.

Current vertically disposed retaining pins including that of AustralianPatent No. 617545 of Esas Corporation require a separate elastic orspring retainer to maintain each pin in its retaining position. In thisexample the pin is maintained in position by compressing an elasticcomponent to generate interference when fitted. Due to the work carriedout by the tooth point members in operation, movement causes frictionalheat to which the elastic material is subjected leading to itsdegradation and subsequent reduced maintaining ability whereby the pinmay fall out of its retaining position.

Notwithstanding the prior art as aforementioned, I have considered thereremains a need for substantial improvements in locking pin arrangementsfor such tooth point members, particularly to overcome presentdisadvantages arising from the manner in which the parts currently locktogether and are difficult to access and to remove, as well as currenttendencies for the pins to be insecure or to fall out. Thus, myinvention aims to provide a novel form of retaining pin means which maybe simply used to achieve efficiency in those aspects in which previousconstructions have been found wanting. In particular, the invention aimsto provide an improved retaining pin means which will allow quickreplacement of tooth point members when necessary but which will remainfirmly in retaining disposition between replacement times.

It is a further object of the invention to provide a retaining pin thatdoes not require any form of deformation or compression to remain in itsretaining position and does not undergo degradation during use so thatit may be used more than once.

DISCLOSURE OF THE INVENTION

With the foregoing and other objects in view, the invention residesbroadly in an excavating tooth assembly of the type having:

an adaptor provided with a forwardly disposed nose portion and arearwardly disposed base portion;

a ground-engaging tooth point member having a socket formed in its rearsection for receiving said nose portion of said adaptor, and

pin means extending through and releasably inter-securing said toothpoint member and said nose portion of said adaptor, said pin means beingpassed through apertures in opposed spaced walls of the tooth pointmember defining said socket and through registering aperture means ofthe nose portion when the latter is received in said tooth point member;

characterized in that said pin means comprises pin members including (1)one or more elongate holding members adapted to be inserted lengthwisein entry attitude and then to be moved widthwise to cause engagementmeans on the or each holding member to engage complimentary portions ofthe aperture surrounds and assume operative attitude, and (2) a lockingmember adapted to be inserted after the or each holding member has beenmoved widthwise and adapted to lock said holding member or members inoperative attitude.

It is preferred that said pin members assume a parallel layeredformation when they are in their operative attitudes and are so made andarranged as to coact and be retained firmly but removably whilerigidifying and maintaining the combined effective width of the pinmembers in their operative attitudes. It is also preferred that saidengagement means on the or each elongate holding member includes ashoulder at each end adapted to receive therebetween a wall portion atsaid aperture means of said nose portion, said shoulders acting topermit the aforementioned widthwise movement of the or each holdingmember.

In one preferred embodiment of the invention said pin means has a singleholding member and the locking member is insertable when said holdingmember is in its operative attitude and retained firmly but removablybetween said holding member and a wall portion of said nose portion. Itis further preferred that the locking member and holding member inlayered formation have their direction through the layers disposedparallel to the direction in which the nose portion and tooth pointmember extend in operation.

In another embodiment of the invention the pin means comprises threeelongate pin members including two holding members and a locking memberin parallel sandwich-layer formation when operative and each extendingthrough or within the apertures in the direction between said opposedspaced walls, and wherein:

the first holding member is freely insertable lengthwise in entryattitude and then movable widthwise to cause said engagement meansthereon to engage said complimentary portions of the aperture surroundsand assume operative attitude;

the second holding member is insertable lengthwise in entry attitudewhen the first holding member is in operative attitude and is thenmovable widthwise to operative attitude in the direction away from saidfirst holding member to leave a space therebetween and with the secondholding member also having said engagement means engaging saidcomplimentary portions of the aperture surrounds opposed to the portionsengaged by the first holding member; and

the parts of the pin means are so made and arranged that said lockingmember may be inserted lengthwise and retained firmly but removablybetween the first and second holding members to rigidify and maintainthe combined effective width of the sandwich-layer pin means in thedirection through the layers provided by the three pin members in theiroperative attitudes.

It is further preferred that the three pin members in layered formationhave their direction through the layers disposed transversely inrelation to the direction in which the nose portion and tooth pointmember extend in operation.

In order that the invention may be understood and put into practicaleffect, reference will now be made to the accompanying drawings,wherein:

BEST METHOD OF CARRYING OUT THE INVENTION

FIG. 1 shows in perspective view a typical example of a tooth pointmember and an adaptor which are to be inter-secured but are illustratedin separated relationship and the two pin portions constituting onepreferred embodiment of the novel pin means according to the inventionalso shown in separated relationship;

FIG. 2 shows in cross-section from the side the same features of FIG. 1shown in separated relationship;

3 shows in cross-section from the side the same features of FIG. 2 withthe tooth point member receiving the adapter and having the holdingmember in its operative disposition and the locking member in partyseparated relationship.

FIG. 4 shows in cross-section from the side the same features of FIGS. 2and 3 with the two pin members in their operative dispositions;

FIG. 5 shows in perspective view a tooth point member and adaptor insimilar relationship to FIG. 1 but showing an alternative embodiment ofthe novel pin means according to the invention; and

FIG. 6 shows in perspective view and in separated relationship analternative arrangement of the pin means.

Referring initially to FIGS. 1 to 4 of the drawings, a standard type ofadaptor 10 has a tapered forwardly disposed nose portion 11 and arearwardly disposed base portion 12 for connection operatively to theexcavating implement. The nose portion 11 is adapted to fit closely andwedgedly into a rear socket 13 of the ground-engaging tooth point member14. To receive the pin means, which includes holding member 15 andlocking member 16, the tooth point member 14 has apertures comprisingupper and lower aperture openings 17 of rectangular shape throughopposed side walls defining the socket 13, while the nose portion 11 hasa registering through-aperture 18 of rectangular form. When the noseportion 11 is in the point member 14 (shown in FIGS. 3 and 4) all saidapertures 17 and 19 will be continuous as a rectangular opening ofuniform cross-section through its vertical depth which is the directionin which the pin means will be inserted. It will be apparent that theends of the aperture 19 include side edges 20, and these are engaged inthe assembled attitude by shoulders of the holding member 15 as laterdescribed.

The holding member and locking member 16 are of elongate form and areadapted to be arranged in parallel layer formation when operative sothat each extends vertically in the direction between the opposed spacedwalls at the aperture openings 17.

It will be apparent that the holding member 15 can be freely insertedlengthwise into the opening defined by the apertures 17 and 19 and canthen be moved widthwise in the direction of arrow A so that upper andlower external shoulders 22 and 23 engage the side edges 20 of theopening at the aperture surrounds and the holding member 15 assumes itsoperative attitude (shown in FIGS. 2 and 3).

The locking member 16 is flat having a thickness almost equal to thedistance between the holding member 15 and a side wall 23 of theaperture 19 when the former is in its operative position, thus allowinginsertion of the locking member 16 therebetween. The locking member 16has resilient spaced part 24 sides including side lugs 25 disposedthereon and engageable by locking apertures 26 provided within theaperture 19. The locking member 16 has a width almost equal to thedistance between the two side walls 27 and 28 (shown in FIG. 1) ofoperative 19 where side lugs 25 extend beyond said width. The side lugs25 urge spaced apart sides 24 towards each other to allow insertion ofthe locking member 16 whereby the side lugs 25 slide adjacent the wallsof the aperture 19 until side lugs 25 engage locking apertures 26 wherethe locking member 16 is maintained firmly but removably. The pin meansis now locked in aperture 19 wherein the combined effective width of thetwo pin members lock the holding member 15 in its operative position,(shown in FIG. 4) this being held in the direction of arrow A.

An alternative embodiment of the invention is shown in FIG. 5 whereinthe novel pin means consists of three members, namely a first holdingmember 29, a second holding member 30 and a locking member 31. These areall of elongate form and are adapted to be arranged in parallelsandwich-layer formation when operative so that each extends verticallyin the direction between the opposed spaced walls at the apertureopenings. The first and second holding members 29 and 30 extend fromeach side of the opening, while the holding member 31 is within theaperture means but not as long as the others.

It will be apparent that the first holding member 29 can be freelyinserted lengthwise into the opening defined by the aperture means andcan then be moved widthwise so that the shoulders 32 and 33 engage theside edges 34 of the opening at the aperture surrounds and the holdingmember 29 assumes its operative attitude. The second holding member 30can then be inserted lengthwise once the first holding member 29 is inposition to allow it to pass comfortably, whereafter the second holdingmember 30 is also movable widthwise to operative position opposite thefirst holding member 29 and thus leaving a space therebetween, thesecond holding member 30 also engaging the aperture surround and edge 34but at the opposite side to the first holding member 29.

It will be seen that the maintaining portion 31 is similar inconstruction to that shown in FIGS. 1 to 4 including solid side portions35 having side lugs 36 disposed thereon and engageable by lockingapertures 37 provided within the aperture 38. In this case the side lugs36 are urged into locking apertures 37 by a resilient rubber fillerblock 39. Other types of bias means could be used if so desired, butthis embodiment illustrates the many additional variations which may beintroduced if so desired.

An alternative type of pin means shown in FIG. 6 includes first andsecond retainer portions insertable in a similar way to the previouslyby described embodiment.

In this case, the locking member 42 is a flat plate with end tabs 40having shoulders 41 at each side, and this has a thickness almost equalto the distance between the first and second holding members when thelatter are in operative positions, thus allowing insertion of thelocking member 42 therebetween. To facilitate this, the first holdingmember 43 has upper and lower ramps 44 as illustrated on either side ofa hinge shoulder 45 so that the holding member or plate 42 may beinserted lengthwise and retained firmly but removably to rigidify andmaintain the combined effective width of the three pin members in thedirection through the layers, this being the direction of arrows D andE.

The second holding member 46 has upper and lower arcuate grooves andreceiving slots 47 so that the inserted end of the locking member 42 canenter and permit a skew disposition in passing the hinge shoulder 45,whereafter the locking member 42 can be brought to a dispositionparallel to the other two and will lock into position by the tabs 40being within the medial vertical groove 48 of the second holding memberand the shoulders 41 held on locating surfaces 49 of the second holdingmember 46. The groove 48 ensures that the locking member 42 can beremoved when it becomes necessary to change the point member, but thisinvolves a positive "seek and remove" action so that accidental releaseat normal times cannot occur.

While the illustrated embodiments will be found very effective inachieving the objects from which the invention has been devised thisspecification is directed to persons skilled in the art who willappreciate that very many further modifications of constructional detailand design may be made, without departing from the broad scope and ambitof the invention, the general nature of which has been set forth herein.

I claim:
 1. A demountable excavator tooth assembly comprising a basemember having a coupling portion, and a tooth member having a couplingportion complementary to that of the base member, each of said couplingportions having an aperture which is in register with the other whensaid base and tooth members are assembled, a holding member having alength and width having coupling portions engageable with complementaryportions of the assembled base and tooth members and a locking member,and wherein the holding member is insertable lengthwise in entryattitude through said registering apertures and then movable widthwiseto cause said holding member to seat the complementary portions of theassembled base and tooth members and assume operative attitude, and alocking member slidably insertable in the registering apertures, saidholding member and said locking member each having parallel surfacesadapted to engage each other and said base member, whereby all of saidsurfaces are parallel to each other and remain parallel with respect toeach other to maintain the holding member seated on the complementaryportions of the assembled base and tooth members preventing lengthwisewithdrawal movement of the holding member.
 2. An assembly as claimed inclaim 1, wherein the coupling portion of the holding member has a femaleformation which engages a complementary male formation of the basemember.
 3. An assembly as claimed in claim 2, wherein said complementarymale formation of the base member is part of the coupling portion of thebase member.
 4. An assembly as claimed in claim 3, wherein the femaleformation of the holding member has spaced protrusions which abutmutually oppositely facing surfaces of the base member.
 5. An assemblyas claimed in claim 4, wherein the said protrusions protrude from theholding member transversely of the registering apertures.
 6. An assemblyas claimed in claim 1, further comprising detent means effective to holdthe locking member in said position within the registering aperturesadjacent the holding member.
 7. An assembly as claimed in claim 6,wherein the detent means comprises a resiliently deformable detentportion of said locking member engageable with a detent hollow in a wallof said aligned apertures when the locking member is in its saidposition within the registering apertures.
 8. An assembly as claimed inclaim 7, wherein the holding member abuts one side of the alignedapertures and the locking member fits snugly between the holding memberand the opposite side of the aligned apertures.
 9. An assembly asclaimed in claim 1, including a pair of holding members each having acoupling portion engaged with the assembled base and tooth members so asto prevent withdrawal movements of those holding members and held spacedapart within aligned apertures by the locking member.
 10. An assembly asclaimed in claim 9, wherein the locking member fits snugly between thepair of holding members.
 11. An assembly as claimed in claim 10, whereinthe locking member in its operative position fits within a groove in oneof the holding members so as to be constrained against withdrawal butwhich can be moved to a skewed position relative to the holding membersin which it can be withdrawn from its position between those twomembers.